Drilling mud weight recorder



P 9, 1952 w. J. BIELSTEIN 2,609,681

DRILLING MUD WEIGHT RECORDER Filed May 13, 1948 TZECQEDIN pszEssuEE GAGE Am: CHART Ana FEED ELEMENT E y 6 COLUMN N L INDICATING ELEMENT PEEsswzE GAGE MUD I OvEEFEow :i 5 10 MUD U CHAMEaEQ WATER 4 CHAMEER G T w MUD L Y F'LuuD L\NE. FEED FLEXiEaLE.

DI ApHnzAew CJEzZterJ. bL'eZabEL'n' San Enter 7 (ltbornEg Patented Sept. 9, 1952 DRILLING MUD WEIGHT RECORDER Walter J. Bielstein, Houston, Tex., assignor, by

mesne assignments, to Standard Oil Development Company, Elizabeth, N. J., a corporation of Delaware Application May 13, 1948, Serial No. 26,788

2 Claims. 1

The present invention is concerned with an improved apparatus for determining the density of a semi-fluid or mud. The invention is more particularly directed to an improved apparatus for determining the density of a drilling mud employed in the recovery of fluids from subterranean areas. In accordance with the present invention the semi-fluid solid is caused to flow through one section or area of an apparatus which is separated from a second section or area of said apparatus by means of a flexible diaphragm. As the density of the mud or semifluid varies in the initial section of the apparatus, the position of the diaphragm varies. This variance of the diaphragm reacts on a fluid maintained in the second section of the apparatus causing it to raise or lower in a column element. Air is forced through said column element and the pressure required to force the air through the water column recorded.

It is well known in the art to recover fluids from subterranean areas as, for example, petroleum oils, gases and the like. In these operations a well borehole is drilled through overlying strata into the formations containing the desirable fluids. The well digging operation is generally conducted utilizing drilling rigs which are well known in the art and at the same time circulating drilling muds. These muds are utilized for several purposes one of which is to remove the cuttings from the well hole bottom. The mud also serves to maintain the desirable hydrostatic head so that the well does not blow when a pressure area is pierced. It is obvious as the drilling operation proceeds the consistency of the mud will vary as well as its density. It is also obvious that hydrostatic head will vary. In order to properly conduct a well hole digging operation, it is essential that the density of the circulating drilling fluid be known at all times. Various suggestions have been made directed toward solving this problem. None of them have been entirely satisfactory.

In accordance with the present invention, an improved apparatus is employed which efliciently and continuously evaluates and records the density of the circulating drilling mud.

The invention will be readily understood by reference to the drawing illustrating one embodiment of the same. Referring specifically to the drawing, the apparatus comprises a mud chamber Ill and a water or other suitable fluid chamber 20. Chambers ill and 20 are separated by means of a flexible diaphragm l. The integral apparatus comprises chambers It and 20 and is L-shaped in character. Positioned on top of chamber 20 is a cylindrical column element 2 Y which, for the purpose of description, is assumed to be a glass tube. concentrically disposed within element 2 is an air feed cylindrical tube 3. Tube 3 extends into chamber 20.

In operation, mud is introduced into the lower area of chamber In by means of line or conduit 4; The mud flows upwardly through chamber In and overflows out through a suitable pipe or overflow element 5. As the density and thus the hydrostatic head of the mud varies, the pressure and force on one face of the flexible diaphragm will vary and change. Thus the position of the diaphragm will change and will exert a varying pressure on the fluid in chamber 2t. For the purpose of description, it is assumed that the fluid in chamber 20 comprises water. The fluid is introduced or withdrawn from chamber 20 by means of line 6. Sufiicient water is introduced into chamber 2|] to extend upwardly into the area between the outer tube 2 and the inner tube 3.

In operation air is passed through line 3 and the pressure required recorded on suitable means. It is preferred that the pressure be recorded on a recording pressure gauge and chart I which for the purpose of illustration is recorded in pounds per square inch. It is also desirable that a direct reading pressure gauge 8 be utilized. The air flows around the lower lip of tube 3 and upwardly in the area between outside tube 2 and inside tube 3. The air is vented from the top of tube 2.

The invention generally comprises an improved apparatus for continuously recording the density of a fluid. It is particularly adapted for the continuous recording of the density of a drilling mud employed in petroleum oil operations. The apparatus comprises the use of an L-shaped unit having a vertical chamber through which the fluid, the density of which is to be recorded, is passed upwardly. The apparatus comprises a horizontal chamber separated from said vertical chamber by means of a flexible diaphragm which may consist of any suitable material. The horizontal chamber is completely fllled with a fluid which is preferably water. Positioned on the top of said horizontal chamber is a cylinnecessary to pass the gas downwardly is measured. This pressure will vary directly depending upon the headof the fluid through which it is necessary to force the gas or air. The head of the fluid likewise will vary directly depending upon the relative position of the diaphragm which position of the diaphragm will vary directly depending upon the density of the fluid in chamber Ii] since the height is fixed.

The height of the flowing fluid, the density of which is to be measured, may vary appreciably. In general, it is preferred that the height of the head be from 10 to 20 inches, particularly about 12 inches. Any fluid may be employed in water chamber 21], but it is preferred that the fluid be one having a low surface tension. In operation it is desired to fix the static head of the fluid chamber 20 equivalent to the static head of the mud. By doing this, the diaphragm is in a neutral position and will move out of that position only when the mud density changes.

Any suitable gas may be employed in operation although it is preferred that the gas be air. In general, it is preferred that the air be dried prior to introducing the same into the apparatus. The height of the water above the center line of the diaphragm in the tubes may vary appreciably, but is generally in the range from about 12" to about 26.9", which is equivalent to and a contiguous second fluid chamber of substantially less vertical height than said first chamber, said first and second chambers having a common wall element consisting of a flexible diaphragm, a first vertical tubular element fixed to said second chamber in fluid intercommunication therewith, said first tubular element extending above the said first chamber, a second tubular element of smaller diameter than said first tubular element and positioned within said first tubular elementand extending into said second chamber, means for passing a gas downwardly within said second tubular element into fluid maintained within said second chamber, whereby the said gas flows upwardly in the space between said first and second tubular elements and is released at the top of the said first tubular element, and means for indicating the pressure necessary to force said gas through said fluid as described.

2. Apparatus as defined in claim 1 wherein water is maintained in said static fluid chamber.

WALTER J. BIELSTEIN.

CES CITED The following references are of record in the file of this patent:

UNITED STQTES PATENTS OTHER REFERENCES A. P. C. application of Rodanet, Ser. No. 362,231, published May 4, 19%3, which has become abandoned. 

